I had a similair problem with my 2001 1.8 Zetec, where it would cut out, usually as i was approaching a junction and de clutched. The speedo is also iratic, the garage i took it into did a diagnostics check which came back clear, but they removed the throttle valve and cleaned it up (it gets a bulid up of carbon) before replacing it. This has sorted the problem of cutting out, maybe you have the same problem. The speedo issue appears an additional problem, which the garage is currently working on resolving.